I 
"^""rer^ss?™'}    Practical  Notes  from  Foreign  Journals.  59 
cold,  and  the  precipitate  filtered  in  a  short  time  (one  hour). — Pharm. 
Zeitschr.  f.  RussL,  18S1.  Keprint. 
[The  sources  of  error  pointed  out  above  are  avoided  by  following 
the  process  as  modified  by  Dr.  De  Yrij  in  "Amer.  Jour.  Phar.,''  1880,, 
p.  394,  in  which,  however,  the  precipitation  of  quinine  in  the  cold  is 
recommended,  and  the  subsequent  heating  of  the  mixture  in  a  water- 
bath,  so  as  to  obtain  the  herapathite  crystallized.  Editor.] 
Estimation  of  Alkaloids  in  Cinchona  5ar^.— Prollius  observed  that 
if  a  mixture  of  38  grams  alcohol,  10  grams  chloroform,  2  grams 
ammonia  water,  and  5  grams  cinchona  bark,  is  agitated  in  a  stoppered 
bottle,  a  wine-red  liquid  is  obtained,  containing  all  the  cinchona  alka- 
loids. On  mixing  the  clear  decanted  liquid  w^ith  5  grams  finely  levi- 
gated calcium  hydrate,  it  is  at  once  decolorized,  and  on  slow  evapora- 
tion the  quinine  is  left  of  a  resinous  appearance,  while  the  other  alka- 
loids are  crystalline.  From  the  weight  of  the  decanted  liquid  the 
weight  of  the  cinchona  bark  represented  therein  is  easily  calculated, 
and  the  percentage  of  alkaloids  from  the  weight  of  the  residue  obtained 
on  evaporation. 
A  simpler  process  for  ascertaining  the  percentage  of  quinine  and  of 
the  other  alkaloids  soluble  in  ether  is  as  follows  :  A  mixture  is  made 
of  88  ether,  4  ammonia  water  and  8  alcohol,  the  latter  serving  merely 
for  uniting  the  ammonia  with  the  ether.  Thirty  grams  of  this  mix- 
ture are  well  agitated  during  several  hours  with  3  grams  powdered 
cinchona  bark ;  20  grams  of  the  clear  solution,  containing  the  alka- 
loids jn  question,  on  being  mixed  with  a  slight  excess — 5  or  6  drops 
— of  dilute  sulphuric  acid,  separate  a  thick  solution  of  the  alkaloidal 
salts,  from  which  the  ether  may  be  readily  decanted;  the  latter 
should  be  well  agitated  with  2  grams  and  then  with  1  gram  of  water j, 
in  order  to  obtain  all  the  alkaloids.  The  mixed  aqueous  solutions  are 
heated  to  expel  all  the  alcohol,  and,  while  still  warm,  precipitated  with 
ammonia.  The  weight  of  the  precipitate,  after  washing  and  drying, 
multiplied  with  50,  indicates  the  percentage  of  the  alkaloids  soluble 
in  ether. 
The  alkaloids  may  also,  though  less  correctly,  be  weighed  as  sul- 
phates, if  the  etherial  tincture  is  freed  from  ammonia  by  agitation 
with  water,  and  then  very  carefully  neutralized  with  dilute  sulphuric- 
acid,  when  the  sulphates  will  at  once  crystallize  out;  a  slight  excess 
of  acid  will  readily  dissolve  these  salts. — Archiv  d.  PJufv.,  August^ 
1881,  85-87. 
